Inflight entertainment (IFE) systems have evolved significantly over the last 25 years. Prior to 1978, IFE systems consisted of audio-only systems. In 1978, Bell and Howell (Avicom Division) introduced a group viewing video system based on VHS tapes. In 1988, Airvision introduced the first in-seat video system allowing passengers to choose among several channels of broadcast video. In 1997, Swissair installed the first interactive video on demand (VOD) system. Currently, many IFE systems provide VOD with full digital video disc (DVD)-like passenger controls.
Most IFE systems are head end centric. In head end centric IFE systems, passengers using seat end equipment access selected prerecorded video programs (e.g., movies, television shows, video games, etc.) from head end equipment “on demand” during the flight by sending program requests that are fulfilled by the head end equipment. The head end equipment fans-out the selected prerecorded video programs to the seat end equipment over a distribution system. In order for these IFE systems to remain fully operational, the head end equipment, distribution system and seat end equipment must all remain operational. Moreover, if the head end equipment or the distribution system becomes inoperable during a flight, the entire IFE system goes down. Unfortunately, this is a fairly common occurrence in many deployed head end centric IFE systems. To address these problems, seat end centric IFE systems have been proposed.
In seat end centric IFE systems, seat end equipment hosts a complete library of prerecorded video programs. The head end equipment and the distribution system are used primarily for preloading the complete video library onto the seat end equipment. The IFE system remains operational during a flight as long as the seat end equipment remains powered, eliminating the risk that the IFE system will become inoperable in flight due to a head end equipment or distribution system failure. However, seat end centric IFE systems have the major drawback that the entire video library must be copied to each seat (typically 200 to 500 seats) or at least each seat group, whereas in head end centric IFE systems copying of the entire video library is generally only performed a few times on head end equipment for the sake of redundancy. Therefore, proposed seat end centric IFE systems require far more storage capacity and loading time than head end centric IFE systems.
In a compromise between head end centric and seat end centric IFE systems, IFE systems have been proposed that preload part of the video library from the head end equipment to the seat end equipment. In these compromise systems, playlists identifying subsets of programs from the video library are selected and the identified programs are downloaded to each passenger seat. The playlists may be customized for each flight or each passenger based on program popularity, passenger demographics and/or passenger preferences. While these systems do not risk the system wide outages of head end centric IFE systems and do not require the large storage capacity of seat end centric IFE systems, the loading time required to preload programs from playlists to each passenger seat on each flight can be very extensive.